There might be several reasons for this problem:

1. The temp path in the preferences is not correct .

2.The Unzip32.dll in windows\system32 does not work with the blobs.

Try  replacing this file with one from  another machine.

3. If it happens only with a specific form, try to edit the sheet by regenerating the sheet,  use  the option " select used columns ".

This kind of problem  might occur in all intools versions.

The spec sheet data is in the domain level so it infercts all the projects.

When the temp path is wrong or the dll is not in the right version the system can't extract the blob from the database and insert the relevant data to the sheet.When it happens with specific form it might come from the fact that the sheet has more then 700 rows.If you regenerate the sheet and  decrease the numbers of the columns it might help.

Since it's not a database problem no need to run any sql to find the source of the promblem.